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Результаты 611-620 из 2,513
Benzo[a]pyrene modulates the biotransformation, DNA damage and cortisol level of red sea bream challenged with lipopolysaccharide Полный текст
2014
Bo, Jun | Gopalakrishnan, Singaram | Chen, Fang-Yi | Wang, Ke-Jian
In animals, biotransformation and the immune system interact with each other, however, knowledge of the toxic mechanism of benzo[a]pyrene (BaP) on these two systems is not well known. The present study investigated the toxic effects of BaP on the biotransformation system, cortisol level and DNA integrity of red sea bream (Pagrus major). The results showed that cortisol level was induced under the challenge of lipopolysaccharide (LPS). Short-term exposure (96h) of BaP at environmental concentration significantly increased the cortisol level, hepatic EROD activity and CYP1A1 mRNA expression. When P. major was exposed to BaP for 14 d followed by LPS challenge this increased the cortisol level, EROD activity and hepatic DNA damage except CYP1A1 mRNA expression. Combined with our previous data, which showed that BaP exposure can modulate the immunologic response in P. major challenged with LPS, a hypothetical adverse outcome pathway of BaP on fish was suggested.
Показать больше [+] Меньше [-]Spatial relations of mercury contents in Pike (Esox lucius) and sediments concentration of the Anzali wetland, along the southern shores of the Caspian Sea, Iran Полный текст
2014
Zamani-Ahmadmahmoodi, Rasool | Bakhtiari, Alireza Riyahi | Rodríguez Martín, José Antonio
Spatial relations of mercury contents in Pike (Esox lucius) and sediments concentration of the Anzali wetland, along the southern shores of the Caspian Sea, Iran Полный текст
2014
Zamani-Ahmadmahmoodi, Rasool | Bakhtiari, Alireza Riyahi | Rodríguez Martín, José Antonio
In recent decades, the Anzali wetland has been threatened and destroyed by environmental pollution from several sources. The purpose of this study was to determine the possible relationships between mercury concentrations in Pike and their respective sediments within the assumed multiple activity center scales of Pike (100, 250 and 500m in radius). To gain a better understanding spatial distribution pattern of Hg in sediments and to pursue the main purpose of this study, kriging (geostatistic spatial interpolation method) was applied. Poor relationships were found between mercury concentrations of Pike and sediments within the assumed multiple activity center scales of Pike. The mercury sediment influence diminished with the increasing radii of assumed activity centers. The results of the present study indicate that fish and sediment mercury concentrations in western parts of the Anzali wetland were low in comparison with the concentrations reported in the literature from other regions.
Показать больше [+] Меньше [-]Spatial relations of mercury contents in Pike (Esox lucius) and sediments concentration of the Anzali wetland, along the southern shores of the Caspian Sea, Iran Полный текст
2014
Zamani-Ahmadmahmoodi, R. | Bakhtiari, A. R. | Rodríguez Martín, José Antonio
In recent decades, the Anzali wetland has been threatened and destroyed by environmental pollution from several sources. The purpose of this study was to determine the possible relationships between mercury concentrations in Pike and their respective sediments within the assumed multiple activity center scales of Pike (100, 250 and 500. m in radius). To gain a better understanding spatial distribution pattern of Hg in sediments and to pursue the main purpose of this study, kriging (geostatistic spatial interpolation method) was applied. Poor relationships were found between mercury concentrations of Pike and sediments within the assumed multiple activity center scales of Pike. The mercury sediment influence diminished with the increasing radii of assumed activity centers. The results of the present study indicate that fish and sediment mercury concentrations in western parts of the Anzali wetland were low in comparison with the concentrations reported in the literature from other regions. © 2014 Elsevier Ltd.
Показать больше [+] Меньше [-]A baseline study of metal contamination along the Namibian coastline for Perna perna and Choromytilus meridionalis Полный текст
2014
Dahms, S. | van der Bank, F.H. | Greenfield, R.
The use of bivalves such as the brown mussel (Perna perna) and the black mussel (Choromytilus meridionalis) is common in the study of marine pollution and the effect of these pollutants on ecosystems and are important in both economic and ecological roles. Namibian marine ecosystems are threatened by pollution from mining, commercial fishing and population growth. The aims of this study were to determine baseline metal concentrations, spatial variation and variation between species. Metal levels in C. meridionalis from Guano Platform (GP) are the lowest of all the sites. The most polluted sites are Rocky Point (RP), Halifax Island (HIL) and between Walvis Bay and Swakopmund (WS). The bioaccumulation of metals between P. perna and C. meridionalis were not uniform for all metals. Overall the study indicates the condition of the coastline to be mostly normal, with Cd and Pb levels being of concern.
Показать больше [+] Меньше [-]Spatial variability in community composition on a granite breakwater versus natural rocky shores: Lack of microhabitats suppresses intertidal biodiversity Полный текст
2014
Aguilera, Moisés A. | Broitman, Bernardo R. | Thiel, Martin
Strong differences have been observed between the assemblages on artificial reefs and on natural hard-bottom habitats worldwide, but little is known about the mechanisms that cause contrasting biodiversity patterns. We examined the influence of spatial attributes in relation to both biogenic and topographic microhabitats, in the distribution and composition of intertidal species on both artificial and natural reefs. We found higher small-scale spatial heterogeneity on the natural reef compared with the study breakwater. Species richness and diversity were associated with a higher availability of crevices, rock pools and mussels in natural habitats. Spatial distribution of certain grazers corresponded well with the spatial structure of microhabitats. In contrast, the lack of microhabitats on the breakwater resulted in the absence of several grazers reflected in lower species richness. Biogenic and topographic microhabitats can have interactive effects providing niche opportunities for multiple species, explaining differences in species diversity between artificial versus natural reefs.
Показать больше [+] Меньше [-]Ecological effects of contaminated sediments following a decade of no industrial effluents emissions: The Sediment Quality Triad approach Полный текст
2014
Lopes, Marta Lobão | Rodrigues, Ana Maria | Quintino, Victor
Ecological effects of contaminated sediments following a decade of no industrial effluents emissions: The Sediment Quality Triad approach Полный текст
2014
Lopes, Marta Lobão | Rodrigues, Ana Maria | Quintino, Victor
Sediments contaminated by industrial effluents a decade after the emissions were stopped were statistically compared to sediments from reference channels, using the Sediment Quality Triad approach. The metals and metalloid concentrations, mainly Hg and As, increased towards the upper part of a contaminated channel, where the industrial discharge was located. A bioaccumulation assay with Scrobicularia plana showed the highest bioaccumulation and mortality in the most contaminated sediments and bioaccumulation strongly correlated with the sediments metals and metalloid concentrations. The resident macroinvertebrate community also showed significant differences between the contaminated and reference channels, in the upper areas, where the community was most affected. All three elements of the quality triad rejected the null hypothesis and indicated that despite the emissions ceasing in 2004, sediments remain contaminated by high levels of metals and metalloid, leading to bioaccumulation and with severe community level consequences.
Показать больше [+] Меньше [-]Ecological effects of contaminated sediments following a decade of no industrial effluents emissions: the Sediment Quality Triad approach Полный текст
2014 | 1000
Lopes, Marta Lobão | Rodrigues, Ana Maria | Quintino, Victor
Sediments contaminated by industrial effluents a decade after the emissions were stopped were statistically compared to sediments from reference channels, using the Sediment Quality Triad approach. The metals and metalloid concentrations, mainly Hg and As, increased towards the upper part of a contaminated channel, where the industrial discharge was located. A bioaccumulation assay with Scrobicularia plana showed the highest bioaccumulation and mortality in the most contaminated sediments and bioaccumulation strongly correlated with the sediments metals and metalloid concentrations. The resident macroinvertebrate community also showed significant differences between the contaminated and reference channels, in the upper areas, where the community was most affected. All three elements of the quality triad rejected the null hypothesis and indicated that despite the emissions ceasing in 2004, sediments remain contaminated by high levels of metals and metalloid, leading to bioaccumulation and with severe community level consequences.
Показать больше [+] Меньше [-]Distribution and recovery trajectory of Macondo (Mississippi Canyon 252) oil in Louisiana coastal wetlands Полный текст
2014
Turner, R Eugene | Overton, Edward B. | Meyer, Buffy M. | Miles, M. Scott | McClenachan, Giovanna | Hooper-Bui, Linda | Engel, Annette Summers | Swenson, Erick M. | Lee, James M. | Milan, Charles S. | Gao, Heng
We measured the concentration of petroleum hydrocarbons in 405 wetland sediment samples immediately before the April 2010 Deepwater Horizon disaster led to their broad-scale oiling, and on nine trips afterwards. The average concentrations of alkanes and PAHs were 604 and 186 times the pre-spill baseline values, respectively. Oil was distributed with some attenuation up to 100m inland from the shoreline for alkanes, but increased for aromatics, and was not well-circumscribed by the rapid shoreline assessments (a.k.a. SCAT) of relative oiling. The concentrations of target alkanes and PAHs in June 2013 were about 1% and 5%, respectively, of the February 2011 concentrations, but remained at 3.7 and 33 times higher, respectively, than in May 2010. A recovery to baseline conditions suggests that the concentration of alkanes may be near baseline values by the end of 2015, but that it may take decades for the PAH concentrations to be that low.
Показать больше [+] Меньше [-]Transforming management of tropical coastal seas to cope with challenges of the 21st century Полный текст
2014
Sale, Peter F. | Agardy, Tundi | Ainsworth, Cameron H. | Feist, Blake E. | Bell, Johann D. | Christie, Patrick | Hoegh-Guldberg, Ove | Mumby, P. J. (Peter J.) | Feary, David A. | Saunders, Megan I. | Daw, Tim M. | Foale, Simon J. | Levin, Phillip S. | Lindeman, Kenyon C. | Lorenzen, Kai | Pomeroy, R. S. (Robert S.) | Allison, Edward H. | Bradbury, R.H. | Corrin, Jennifer | Edwards, Alasdair J. | Obura, David O. | Sadovy de Mitcheson, Yvonne J. | Samoilys, Melita A. | Sheppard, Charles R.C.
Over 1.3 billion people live on tropical coasts, primarily in developing countries. Many depend on adjacent coastal seas for food, and livelihoods. We show how trends in demography and in several local and global anthropogenic stressors are progressively degrading capacity of coastal waters to sustain these people. Far more effective approaches to environmental management are needed if the loss in provision of ecosystem goods and services is to be stemmed. We propose expanded use of marine spatial planning as a framework for more effective, pragmatic management based on ocean zones to accommodate conflicting uses. This would force the holistic, regional-scale reconciliation of food security, livelihoods, and conservation that is needed. Transforming how countries manage coastal resources will require major change in policy and politics, implemented with sufficient flexibility to accommodate societal variations. Achieving this change is a major challenge – one that affects the lives of one fifth of humanity.
Показать больше [+] Меньше [-]Multivariate statistical approach to identify significant sources influencing the physico-chemical variables in Aerial Bay, North Andaman, India Полный текст
2014
Jha, Dilip Kumar | Vinithkumar, N.V. | Sahu, Biraja Kumar | Das, Apurba Kumar | Dheenan, P.S. | Venkateshwaran, P. | Begum, Mehmuna | Ganesh, T. | Prashanthi Devi, M. | Kirubagaran, R.
Aerial Bay is one of the harbor towns of Andaman and Nicobar Islands, the union territory of India. Nevertheless, it is least studied marine environment, particularly for physico-chemical assessment. Therefore, to evaluate the annual spatiotemporal variations of physico-chemical parameters, seawater samples collected from 20 sampling stations covering three seasons were analyzed. Multivariate statistics is applied to the investigated data in an attempt to understand the causes of variation in physico-chemical parameters. Cluster analysis distinguished mangrove and open sea stations from other areas by considering distinctive physico-chemical characteristics. Factor analysis revealed 79.5% of total variance in physico-chemical parameters. Strong loading included transparency, TSS, DO, BOD, salinity, nitrate, nitrite, inorganic phosphate, total phosphorus and silicate. In addition, box-whisker plots and Geographical Information System based land use data further facilitated and supported multivariate results.
Показать больше [+] Меньше [-]Leaf injury and gas exchange in Ipomoea nil cv. Scarlett O’Hara, an ozone bioindicator species, in Sao Paulo, Brazil Полный текст
2014
Moraes, Regina M. | Meirelles, Sergio T. | Silva, Simone F. | Silva, Daiane T. | de Assis, Pedro I.L.S. | Viola, Sandra R.A.S.
Ipomoea nil (L.) Roth. cv. ‘Scarlett O’Hara’ was evaluated as a tropical bioindicator species sensitive to ozone (O3). A total of nine field experiments were performed, with 28 days of exposure each. Visible leaf injuries, carbon assimilation (Asat) and stomatal conductance (gs) were quantified and correlated to oscillations in environmental conditions and accumulated ozone exposure over a threshold of 40 ppb h (AOT40). The values of gas exchange and leaf injury continuously varied throughout the study period. Asat and leaf injury (chlorosis) were higher in spring than in others seasons. The gs was higher in autumn. The analyses of the abiotic and biotic variables revealed an opposing trend between the Asat and both leaf injury and AOT40. Ozone levels were moderate and its relationship with gs was inverse. This may be the cause of the moderate injury. ‘Scarlett O’Hara’ is sensitive to O3 and has potential as an O3 bioindicator in sub–tropical regions.
Показать больше [+] Меньше [-]Linking the toxic metals to benthic community alteration: A case study of ecological status in the Bohai Bay Полный текст
2014
Wu, Bin | Song, Jinming | Li, Xuegang
Ecological effects and quality status of sediments in the Bohai Bay (North China) were studied by incorporating the traditional chemical analysis and benthic community structure. In the present study, paired sediments from 20 stations were sampled for chemical analysis and benthic assemblages. The overall results demonstrated that sediment impairment mainly appeared in the southern part of the Bay. The results obtained from the principal component analysis regarding benthic data and potential explanatory factors indicated that As, Hg and petroleum hydrocarbons (PHs) were responsible for the distribution of macrofaunal assemblages. Canonical correspondence analysis further showed As was significantly correlated to the benthic alteration, which provided evidence of ecological relevance to chemical substances of concern. Overall, this study revealed the metal contamination in the Bohai Bay was not as severe as previously regarded. Yet, further investigation is still needed considering the complexity of sediment matrices.
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